Hawaii Geothermal Project : the effect of steady withdrawal of fluid in geothermal reservoirs

Abstract

The problem of combined free and forced convection in geothermal reservoirs resulting from steady withdrawal of fluid is investigated numerically. The aquifer is confined by caprock on the top, heated by an impermeable surface at the bottom, and is recharged continuously from the ocean. The governing quasilinear partial differential equations in terms of pressure and temperature are approximated by finite difference equations which are solved numerically by iteration. Computations were carried out for both cylindrical and rectangular reservoirs for a selected set of parameters. It is found that the withdrawal rates and the location of the withdrawal site have a significant effect on heat transfer and fluid flow characteristics in a geothermal reservoir.